Department of Neuroanatomy and Molecular Brain Research, Ruhr-University Bochum, Bochum 44780, Germany.
Exp Brain Res. 2009 Dec;199(3-4):255-64. doi: 10.1007/s00221-009-1957-4.
Pannexin1 (Panx1) is a novel candidate for an electrical synapse protein in the retina. At present Panx1 is considered to function as a hemichannel. Since information about the gating properties of Panx1 channels to date rely on blocker pharmacology, we have begun to establish a structural context of channel function starting with site directed mutagenesis of cysteine residues in transmembrane domains of Panx1. Dye uptake and whole cell voltage clamp recordings of transfected N2a cells demonstrate that zfPanx1 forms voltage activated hemichannels with a large unitary conductance in vitro. The function of this channel was significantly reduced following mutation of a single cysteine residue (C282W) in the fourth transmembrane region. This result suggests a role of this domain in gating of the Panx1 hemichannel.
缝隙连接蛋白 1（Panx1）是视网膜电突触蛋白的一个新候选蛋白。目前认为 Panx1 作为连接蛋白起作用。由于迄今为止有关 Panx1 通道门控特性的信息依赖于阻断剂药理学，因此我们已经开始通过对 Panx1 跨膜域中的半胱氨酸残基进行定点突变，建立通道功能的结构背景。转染的 N2a 细胞的染料摄取和全细胞电压钳记录表明，zfPanx1 在体外形成电压激活的连接蛋白通道，具有较大的单通道电导。第四跨膜区单个半胱氨酸残基（C282W）突变后，该通道的功能显著降低。这一结果表明该结构域在 Panx1 连接蛋白通道的门控中起作用。
